Liquid filled index matching device for ophthalmic laser procedures

ABSTRACT

There is provided a device for use as an interface between a laser surgery device and the eye of a patient. The device is filled with a liquid that matches the index of refraction of the eye. The device further has a curved lens that follows the curvature of the outer surface of the patient&#39;s eye. In this manner the interface device, through which the laser beam must travel, has essentially the same index of refraction as the eye.

This application claims the benefit of priority of provisional application Ser. No. 61/083,849 filed Jul. 25, 2008, the disclosure of which is incorporated herein by reference. The present invention relates to an apparatus for use in laser surgery on the eye and in particular during laser lens surgery. Thus, the present invention provides for a fluid filled patient interface device that follows the curvature of the patient's eye and reduces changes in the index of refraction between the docking station and the eye.

BACKGROUND OF THE INVENTION

In performing laser surgery on the eye, and in particular in performing laser surgery on the lens of the eye, such as for the purpose of performing a laser assisted capsulotomy, an interface device is needed that touches the anterior surface of the eye and docks with the laser device that is being used to perform the surgery. Such laser devices and systems are disclosed, for example in published applications US 2007/173794 A1, US 2007/173795 A, US2007/185475 A1, WO 2007/084694 A2, WO 2007/084627 A2, the disclosures of which are incorporated herein by reference.

A particular problem that may occur with such interface devices arises because the laser beam must pass through the interface device which has a different index of refraction than the components of the eye that the laser beam must also pass through to reach the lens. This difference in the index of refraction creates difficulties in accurately placing the laser beam at a particular point in the lens of the eye or at particular points in other structures within the eye. Previously, this problem has been addressed by the use of complex mathematical algorithms that attempted to compensate for the difference in the index of refraction. Moreover, this problem is even further increased when the surfaces of the interface device through which the laser beam must travel are not flat.

SUMMARY

It is desirable to develop an interface device that reduces or eliminates these and other undesirable features of such devices. In particular it is desirable to have an interface device that has the same index of refraction as the cornea. In this way the refractive power and effects of the cornea are eliminated without the need to applanate the eye and the detrimental effects of applanation can be eliminated.

The present invention, among other things, solves this need by providing an index matching device comprising: curved patient interface lens; a sidewall; a glass plate; a leg; and, a laser device docking member; wherein the side wall, glass plate and curved patient interface lens form a fluid reservoir.

In a further embodiment, the present invention provides an index matching device comprising: a laser device docking ring; a plurality of legs each having a first and a second end; the first end of each leg being affixed to the laser docking ring; an annular side wall having a first and a second end; the first end of the annular side wall being affixed to the second end of the legs; a glass plate attached to the side wall adjacent to the first end of the side wall; a curved patient interface lens attached to the side wall adjacent the second end of the side wall; the side wall having a filling port; the glass plate, curved patient interface, and side wall forming a fluid reservoir; and the fluid reservoir containing an index matching fluid.

There is yet further provided an index matching device comprising: a fluid reservoir; the reservoir having a shape that in part follows the curvature of the eye; and the reservoir containing a fluid having an index of refraction that matches the index of refraction of a cornea, wherein the index matching device eliminates the refractive p power of the cornea.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional diagram of an index matching device of the present invention.

FIG. 2 is a cross section diagram of an index matching device of the present invention.

FIG. 3 is a detailed cross section diagram of an index matching device of the present invention showing the side wall ledge and curved patient interface lens.

DESCRIPTION OF THE DRAWINGS AND THE PREFERRED EMBODIMENTS

The present invention provides for a laser patient interface device that is fluid filled, with a fluid that matches the index of refraction of the anterior chamber of the eye and thus greatly reduces any difference in the index of refraction between the eye and the interface device.

In general, as shown in FIG. 1, there is provided an index matching device for use in the performance of ophthalmic laser surgery. Thus, there is provided by way of example a curved patient interface lens 1, a fluid reservoir 2, a side wall for the reservoir 3, a filling port 4 for the reservoir 2, and a glass plate 5. The side wall 3 is circular and the side wall 3, glass plate 5 and curved patient interface lens 1 are connected together in a manner that is fluid tight to form the fluid reservoir 2.

The reservoir 2 can be filled with a fluid having a known index of refraction and thus the index of refraction can be set to match and/or approximate the index of refraction of the lens. Thus, the reservoir is preferably filled with a saline solution that has been degassed. Moreover, although the preferred embodiment of the present invention is to match or as closely as possible approximate the index of refractions of the device to that of the eye, in other applications having a known and predetermined difference may be advantageous. Thus, the reservoir may be filled with a particular index matching fluid having a predetermined and known index of refraction, such as those that are obtainable from NYE and CARGILLE LABS.

The curved patient interface lens 1 is shaped to follow the curvature and shape of the anterior surface of the eye. Thus, different shapes and sizes of curved patient interface lens 1 may be employed depending upon the patient. The curved patient interface lens 1 may be a commercially available hard contact lens, or it may be made of similar materials to those used to make such contact lens. The curved lens has a thickness of about that of a contact lens and has a diameter of about 12 to 12.5 mm.

The side wall may be made of plastic or metal. The curved patient interface lens 1 may be attached to the side wall by glue, pressure fit, snap fit or other connecting means known to the art, provided that the connection is fluid tight so as to prevent fluid from leaking out of the reservoir. A detail of the manner in which the curved patient interface lens adjoins the side wall is provided in FIG. 3. Thus, in this figure there is provided a curved patient interface lens 31, a reservoir 32, side wall 33, which has a ledge 38 upon which the lens 32 rests. Returning to FIG. 1, there is further shown a filling port 4. The port may be of any type known to the art that will allow for easy filling of the reservoir and which does not leak after being filled. The port may be sealed with an epoxy glue or other sealing means. Alternatively, a small piece of metal tape or other similar material may be used over the top of the port on the outside of the side wall 3 to seal the port after filling. If an aqueous solution is used as the index matching fluid, it is desirable to degass the solution prior to filling to prevent generation of bubbles in the fluid reservoir.

The glass plate 5 is as thin as practicable and may be about 0.5 mm to 2 mm in thickness. The glass plate may have a diameter of about 11 mm. The glass plate may be affixed to the device by glue, pressure fit or other techniques known to the art that would provide a fluid tight seal.

The side wall 3 is connected to legs 6 which are connected to ring 7. The ring 7 is the portion of the device that is attached, or docked with, the laser surgery device. Thus, the shape of this ring is dependent upon and should match with the docking features of the laser surgery device. A different embodiment of the legs and ring are shown in FIG. 2. In that figure there is only a single leg. Thus, there is provided a curved patient interface lens 21, a reservoir 22, a side wall 23, a filling port 24, a glass plate 25, a single leg 26 and a docking member 17. The docking member 17 does not necessarily have to be a ring or circular.

From the foregoing description, one skilled in the art can readily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and/or modifications of the invention to adapt it to various usages and conditions. 

1. An index matching device comprising: a. a curved patient interface lens; b. a sidewall; c. a glass plate; d. a leg; and, e. a laser device docking member; f. wherein the side wall, glass plate and curved patient interface lens form a fluid reservoir.
 2. The device of claim 1, wherein the fluid reservoir is filled with saline.
 3. The device of claim 2, wherein the fluid reservoir is filled with a fluid having a predetermined index of refraction
 4. The device of claim 1, wherein the index matching device eliminates the power of the cornea.
 5. An index matching device comprising: a. a laser device docking ring; b. a plurality of legs each having a first and a second end; c. the first end of each leg being affixed to the laser docking ring; d. an annular side wall having a first and a second end; e. the first end of the annular side wall being affixed to the second end of the legs; f. a glass plate attached to the side wall adjacent to the first end of the side wall; g. a curved patient interface lens attached to the side wall adjacent the second end of the side wall; h. the side wall having a filling port; i. the glass plate, curved patient interface, and side wall forming a fluid reservoir; and, j. the fluid reservoir containing a fluid.
 6. The device of claim 5, wherein the index of refraction of the fluid matches the index of refraction of a cornea of an eye, whereby the power of the cornea is eliminated.
 7. The device of claim 5, wherein the index of refraction of the fluid has a predetermined index of refraction that is different than the index of refraction of the cornea of an eye.
 8. An index matching device comprising: k. a fluid reservoir; l. the reservoir having a shape that in part follows the curvature of the eye; and, m. the reservoir containing a fluid having an index of refraction that matches the index of refraction of a cornea.
 9. The device of claim 8, wherein the fluid is saline.
 10. The device of claim 8, wherein the index matching device eliminates the power of the cornea. 